Abstract: This diversity research supplement on Project 3, ?Modeling the Impact of Tobacco Control Policies on Polytobacco Use and Associated Health Disparities,? which is part of the NCI-funded University of Michigan/Georgetown Center for the Assessment of the Public Health Impact of Tobacco Regulations (U54CA229974), will provide three years of funding and professional development/training for Mr. Delvon Mattingly, a PhD student in the Department of Epidemiology at the University of Michigan. Mr. Mattingly is pursuing his research interests in social determinants of tobacco use and other substances, including determinants that are particularly salient for racial/ethnic minorities. The aims of the proposed research are: 1: to evaluate the relationship between perceived discrimination and individual tobacco product use by race/ethnicity and gender; and 2: to evaluate the relationship between perceived discrimination and polytobacco use by race/ethnicity and gender. Mr. Mattingly?s project will complement the aims of Project 3 of the parent grant, which aims to estimate tobacco-related health disparities associated with polytobacco use and to investigate the impact of specific tobacco control policy options on these disparities, by examining discrimination as an understudied social determinant of tobacco-related health disparities, particularly related to polytobacco use and differences by race/ethnicity and gender. Knowledge learned from this diversity supplement may lead to a better understanding of the complex interplay between social determinants and tobacco-related health disparities of polytobacco use among racial/ethnic minorities.